The work vehicles proposed for applications in the related field include work vehicles equipped with an HST traveling hydraulic circuit with a hydraulic pump and a traveling hydraulic motor connected therein through a closed circuit connection (see patent reference literature 1). In the work vehicle disclosed in patent reference literature 1, two traveling hydraulic motors, disposed parallel to each other, are connected to a single hydraulic pump through a closed circuit connection and each hydraulic motor is connected to the front wheels or the rear wheels so as to drive the front wheels and the rear wheels with different hydraulic motors. A variable relief valve is connected to the hydraulic motor for driving the front wheels and the drive torque at the front wheels is controlled by adjusting the relief pressure setting.